static const char* normal_texture_fragment_shader = STRINGIFY(
uniform sampler2D sampler;
varying lowp vec2 texCoordVarying;
void main()
{
    lowp vec4 color = texture2D(sampler, texCoordVarying);
    gl_FragColor = color;//vec4(color.b, color.g, color.r, color.a);
}
);